Transthoracic echocardiography as a predictor of spinal anesthesia-induced hypotension in cesarean section: a prospective observational study

Abstract

Spinal anesthesia-induced hypotension (SAIH) is a common complication during cesarean delivery and is closely associated with maternal intravascular volume status. However, reliable real-time assessment of volume changes remains challenging. This study aimed to evaluate whether transthoracic echocardiography (TTE)-derived ventricular volume parameters could dynamically reflect peri-anesthetic volume changes and predict SAIH. A total of 100 healthy singleton parturients scheduled for elective cesarean delivery under spinal anesthesia were prospectively enrolled. Left ventricular end-diastolic volume (LVEDV) and left ventricular end-systolic volume (LVESV) were measured by transthoracic echocardiography using the biplane Simpson method at three predefined time points: after admission (T1), after crystalloid fluid preloading (T2), and after stabilization of the sensory block (T3). Systolic blood pressure (SBP), mean arterial pressure (MAP), and heart rate (HR) were recorded simultaneously. SAIH was defined as an SBP < 90 mmHg or a decrease of > 30% from baseline. Multivariable logistic regression and receiver operating characteristic (ROC) curve analyses were performed to identify independent predictors of SAIH. Eighty-four parturients completed the study, and 26 (30.95%) developed SAIH. Following crystalloid fluid preloading at T2, both LVEDV and LVESV increased significantly compared with baseline. At T3, parturients who subsequently developed SAIH exhibited significant reductions in LVEDV and LVESV compared with T2. Multivariable logistic regression identified baseline LVEDV (T1) and LVESV (T1) as independent predictors of SAIH ( P = 0.023 and P = 0.010, respectively). The predictive model demonstrated moderate discrimination, with an area under the ROC curve (AUC) of 0.725 (95% confidence interval, 0.600–0.850). TTE-derived LVEDV and LVESV were associated with peri-anesthetic volume changes and demonstrated moderate ability to identify parturients at risk of SAIH. These findings suggest that bedside TTE may provide complementary information for peri-anesthetic volume assessment rather than serving as a standalone predictor. Chinese Clinical Trial Registry (ChiCTR2100042973). February 2, 2021 (Retrospectively registered).